Morphology and immunohistochemical characteristics of the pterygopalatine ganglion in the chinchilla (Chinchilla laniger, Molina)

Abstract

Histological and histochemical investigations revealed that the pterygopalatine ganglion (PPG) in the chinchilla is a structure closely connected with the maxillary nerve. Macro-morphological observations disclosed two different forms of the ganglion: an elongated stripe representing single agglomeration of nerve cells, and a ganglionated plexus comprising smaller aggregations of neurocytes connected with nerve fibres. Immunohistochemistry revealed that nearly 80% of neuronal cell bodies in PPG stained for acetylcholine transferase (CHAT) but only about 50% contained immunoreactivity to vesicular acetylcholine transporter (VACHT). Many neurons (40%) were vasoactive intestinal polypeptide (VIP)-positive. Double-staining demonstrated that approximately 20% of the VIP-immunoreactive neurons were VACHT-negative. Some neurons (10%) in PPG were simultaneously VACHT/nitric oxide synthase (NOS)-or Met-enkephaline (Met-ENK)/CHAT-positive, respectively. A small number of the perikarya stained for somatostatin (SOM) and solitary nerve cell bodies expressed Leu-ENK-and galanin-immunoreactivity. Interestingly about 5-8% of PPG neurons exhibited immunoreactivity to tyrosine hydroxylase (TH). Intraganglionic nerve fibres containing immunoreactivity to VACHT-, VIP-and Met-ENK-were numerous, those stained for calcitonin gene related peptide (CGRP)-and substance P (SP)-were scarce, and single nerve terminals were TH-, GAL-, VIP-and NOS-positive.

Distribution of cocaine- and amphetamine-regulated transcript (CART), neuropeptide Y (NPY) and galanin (GAL) in the pterygopalatine ganglion of the domestic duck (Anas platyrhynchos f. domestica)

“…Galanin presence was demonstrated in the plexuses of the stomach muscular layer of pig and wild boar [27] and in the PPG of pig, chinchilla and cat [37][38][39]. GAL-IR has been observed in chinchilla in a few perikarya (2-3 per section) and in individual intraganglionic nerve fibers of the PPG [38].…”

“…GAL-IR has been observed in chinchilla in a few perikarya (2-3 per section) and in individual intraganglionic nerve fibers of the PPG [38]. In pig PPG a small number (approximately 6%) of GAL-IR neurons and single nerve fibers was found with all GAL-positive neurons containing also VIP [37].…”

An Immunohistochemical Study of Cocaine- and Amphetamine-Regulated Transcript (Cart) Expression in the Pterygopalatine Ganglion of the Pig

“…Interestingly, we failed to visualize somatostatin-IR neuronal elements in the porcine PPG. Previously, it has been reported that a relatively small subpopulation of somatostatin-IR small-sized neurons exists in the porcine [11] and chinchilla's PPG [7]. …”

“…From the morphological point of view, at least two different forms of PPG can be distinguished. Precise macroanatomical studies revealed that PPG may exist as either a large aggregation of nerve cells grouped in a single ganglion or a small plexus containing several smaller in size ganglia [7]. Previous studies have also shown that PPG parasympathetic neurons are predominantly cholinergic by nature, however the presence of other neurotransmitter markers including tyrosine hydroxylase or nitric oxide synthase has been additionally noted [7].…”

“…Precise macroanatomical studies revealed that PPG may exist as either a large aggregation of nerve cells grouped in a single ganglion or a small plexus containing several smaller in size ganglia [7]. Previous studies have also shown that PPG parasympathetic neurons are predominantly cholinergic by nature, however the presence of other neurotransmitter markers including tyrosine hydroxylase or nitric oxide synthase has been additionally noted [7]. Besides, major neurotransmitter PPG neurons also express various neuropeptide receptors [8] as well as a bulk of neuroactive peptides acting as neuromodulators and/or co-transmitters [9][10][11].…”